Trabalho de sistemas distribuídos - middleware

Trabalho sobre Middleware
Exemplos de aplicações cliente-servidor

1. Aplicação JAVA - Corba

package address_book_system; import address_book_system.address_bookPackage.*;

import java.util.Hashtable; import java.util.Enumeration;

//
//
// AddressBookServant
//
// This servant class is responsible for implementing
// three methods
//
// * String name_from_email ( String email );
// * String email_from_name ( String name );
// * void record_user ( String name, String email );
//
//

class AddressBookServant extends _address_bookImplBase
{
private Hashtable name2email;

public AddressBookServant() { // Create a new hashtable to store name & email name2email = new Hashtable(); }

// Get the name of this email user public String name_from_email ( String email ) throws unknown_user { if (name2email.contains(email)) { // Begin search for that name for (Enumeration e = name2email.keys(); e.hasMoreElements();) { String name = (String) e.nextElement(); String e_mail = (String) name2email.get(name);

// Match on email ? if (email.compareTo(e_mail) == 0) { return name; } } }

// User not found - throw unknown user exception throw new unknown_user(); }

// Get the email of this person public String email_from_name ( String name ) throws unknown_user { // If user exists if (name2email.containsKey(name)) { // Return email address return (String) name2email.get(name); }

// User doesn't exist throw new unknown_user(); }

// Add a new user to the system public void record_user ( String name, String email ) throws user_exists { // Is the user already listed if (name2email.containsKey( name ) || name2email.contains( email ) ) { // If so, throw exception throw new user_exists(); }

// Add to our hash table